About the problem of vitrified tiles being pasted to the wall of the kitchen and toilet after proces

It can be pasted, but it affects the appearance. Let me draw a diagram for you to illustrate. The main thing is that the corners will leak gray edges, which is unsightly.

It is also okay for workers to grind this horn. It's more troublesome, though.

The contractor is talking nonsense, and the 45° chamfering workers can do it themselves, maybe they are afraid of trouble. This kind of 45° chamfering is usually only used for the sunny corner, and other places do not need chamfering, and the decoration is generally cut out by the bricklayer master himself with a cutting machine.